New concerns over vulnerability of Antarctic ice sheets

Antarctica's large land-based ice sheets will melt if current warm temperatures continue, according to new research. That would have significant consequences for future sea level rise.

The findings are the result of a study by scientists from New Zealand, the United States, Italy, and Germany.

"This research gives us a look into Earth's potential future if greenhouse gas levels continue to rise and temperatures continue to climb," says lead scientist Richard Levy of GNS Science.

"Basically, large parts of Antarctica, particularly around the coast, will become ice-free. Melting of Antarctica's massive land-based ice sheets will likely take thousands of years, but observations certainly suggest ice sheet melt is well underway.

"I would like to think that we can slow down this glacial retreat or even stop it. I certainly find it hard to imagine Antarctica without its majestic ice sheets."

The scientists found plenty of evidence to demonstrate the relatively warm conditions in Antarctica, including shellfish that are now unable to live on sub-Antarctic Islands .

"Trees, shrubs, and grasses that are similar to those that grow in New Zealand's alpine tundra regions were able to thrive in Antarctica's Dry Valleys, an area that is presently devoid of higher plant life. We also found evidence that the glaciers retreated far from the coast," Dr Levy says.

"Fifteen million years ago West Antarctica had a lot more area sitting above sea level, so it held much more land-based ice than it does today. Therefore we would not expect the same amount of sea level rise from land-based ice melt under similar temperature increase in the future. But the outcome certainly suggests that land-based ice in Antarctica is more susceptible to melt than we previously thought."

Details of the study will be published this week in the Proceedings of the National Academy of Sciences.